Balancing hoist



Dec. 2, 1969 o. M. ULBING 3,481,583

BALANCING HOIST Filed Oct. 20. 1967 5 Sheets-Sheet l INVENTOR 07' MAI?M. UL BIA/G AGENT 0. M1 ULBING BALANCING HOIST Dec. 2, 1969 5Sheets-Shee t 2 Filed Oct. 20, 1967 rppilpiurrlpai. 1

INVENTOR 0mm UL BIA/6 my W74 AGENT Dec. 2, 1969 Filed Oct. 20, 1967 O.M. ULBING BALANC ING HOI ST 5 Sheets-Sheet 3 FIG. 3

INVENTOR OTMAR M. ULB/NG AGENT 1969 o. M. ULBING 7 3,481,583

' BALANCING HOIST Filed Oct. 20, 1967 5 Sheets-Sheet 4 INVENTOR OTMAR M.ULBI/VG United States Patent 3,481,583 BALANCING HOISP Otmar M. Ulbing,Berkshire, N.Y., assignor to Ingersoll- Rand Company, New York, N.Y., acorporation of New Jersey Filed Oct. 20, 1967, Ser. No. 676,877 Int. Cl.B66d N36 US. Cl. 254-168 1 Claim ABSTRACT OF THE DISCLOSURE A balancinghoist using a rotatable ball screw and fixed ball nut for rotational andaxial movement of the drum before a pneumatically displaced piston.

This invention relates to hoists, and in particular to a balancing hoisthaving a simplified arrangement for rotating and translating the drumthereof. Prior art pneumatic hoists have rather complex arrangements, toeffect the rotation and translation of the drum, having many interactingcomponents subject to wear and requiring frequent maintenance services.It is an object of this invention, therefore, to provide an improved andsimplified arrangement for the rotation and translation of the drumwithin the hoist. A feature of this invention comprises the use of arotatable ball screw cooperative with a fixed ball nut acted upon by apiston to rotate and translate the cable drum.

The aforementioned and other objects and features of this invention willbecome more apparent by reference to the following description taken inconjunction with the accompanying drawing which is a cross-sectionalelevational view of the hoist according to the invention less a portionof the trolley support structure.

In FIG. 1 index number 1 is the piston side end cap, 2 the cylindricalmember and 3 the control side end cap. The control end cap carries ballnut 4 which is keyed against rotation by key 5. Ball screw 6 turns inball nut 4 and supports cable drum 7 held by bolt 8 and keyed againstrotation by key 9. Piston 10 acts upon the drum-nut assembly throughthrust bearing 11.

Packing 12 seals the piston 10 against the cylinder 2. Cable shield 13prevents the cable 14 from jumping out of the drum groove 15, and groove16 in the shield permits insertion of a ball 17 swedged to the end ofthe cable 14. This ball 17 is received in slot 18 of the cable cabledrum 7 and anchors the cable 14. Cable replacement, therefore, can bemade without disassembly of the balancer.

It is my teaching to use a ball nut 4 and ball screw 6 to rotate andtranslate the drum 7, in which the ball nut is held stationary and theball screw turned therein and out. While it would seem immaterialwhether the one or the other of the elements is rotated, at heretoforeunexpected benefit arises in stabilizing the ball nut 4 and turning theball screw 6. For one, it is not necessary to penetrate the piston 10with the ball screw 6, and then have to be involved with sealing alongthe penetration. Rather, the screw 6 is fixed to and carried by the drum7; the screw terminates within the drum, leaving intact the surface of"ice the piston 10, and translates therewith. Further, the loading ofthe ball nut 4 is always thereacross. Never does the loading, via thepaying-out of cable 14, get beyond the ball nut, before the ball nut, orbehind it. Loading always occurs across the same cross-sectional area ofthe ball nut, thus the ball nut is never met with variably-displaced,fore and aft loading stresses. This novel feature greatly enhances thelife and maintenance of the two, interacting threaded components.

As set forth in the foregoing, my invention teaches an improved use of afixed ball nut and a rotatable ball screw to derive the benefits thereofwhile avoiding the high mortality known hereto-fore with suchcomponents.

While I have described my invention in connection with specificapparatus, it is to be clearly understood that this is done only by wayof example.

I claim:

1. A balancing hoist, comprising:

a casing, said casing defining a cavity therein;

a drum disposed in said cavity for rotational and axial movementtherein;

a cable wound on said drum having one end extending from said cavity,externally of said casing to receive work loading, the other endreplaceably secured to said drum; and

first means coupled to said casing for causing movement of said drumwithin said cavity; wherein said first means comprises input means forintroducing pressurized fluid to one end of said cavity, means carriedby said casing for supporting said drum for axial movement relative tosaid casing, a ball nut and ball screw cooperative with said supportmeans for rotating said drum during axial movement thereof, and pistonmeans disposed between said input means and said drum, and coupled tosaid drum, to move said drum relative to said support means uponintroduction of pressurized fluid; and wherein said ball nut is fixed tosaid support means and said ball screw is coupled, at either endsthereof, non-penetratively thereof to said piston and penetrativelythereof to said nut, in being abuttingly fixed to said drum andthreadedly engaged with said nut at said either ends, for movement ofsaid screw in unison with said drum and relative to said support means,causing said cable to be payed-out and retrieved along a line ofsuspension which is invariable relative to said support means, uponmovement of said drum and said screw.

References Cited UNITED STATES PATENTS 2,082,633 6/1937 Johnstone188-174 2,868,504 1/1959 Minty 254-168 2,987,786 6/1961 Smith 212-1343,260,508 7/ 1966 Powell 254168 HARVEY C. HORNSBY, Primary Examiner US.Cl. X.R.

